IKEA Trådfri Signal Repeater

My understanding is these are only capable of pairing with bulbs. Very simple.

If you're looking for inexpensive, fast, small motion sensors with great battery life, the Xiaomi are something to consider. You can just buy some IKEA Trådfri Outlets or Repeaters, the Zigbee mesh strengthens, and the Xiaomi seem to be very stable. I have only dropped a Xiaomi leak sensor in the basement by the water main since November 2018 when the outlets were installed. The only thing you need to do is wait. Average delivery time is a month.